1. A 50 kg carton slides at 4 m/s across an icy surface. The sliding carton skids onto a rough surface and stops in 3 seconds. Calculate the force of friction it encounters.

A carton of mass 50-kg slides across an icy surface at a speed of 4 m/s. Conclusion : The momentum of a carton of given mass moving with a particular velocity is 200 kg−m/s .